To compute the standard deviation for a set of scores (e.g., $3, 5, 4, 2, 7, 6, 5$, and $8$, which have a mean of $5$), first determine the difference between each score and the mean. Square each difference to make all values positive, then find the mean of these squared differences (the variance), which is $28 / 8 = 3.50$. Finally, the square root of the variance provides the standard deviation: $\sqrt{3.50} = 1.87$.